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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 | #ifndef _LINUX_BLKDEV_H #define _LINUX_BLKDEV_H #include <linux/major.h> #include <linux/sched.h> #include <linux/genhd.h> #include <linux/tqueue.h> #include <linux/list.h> #include <linux/pagemap.h> #include <asm/scatterlist.h> struct request_queue; typedef struct request_queue request_queue_t; struct elevator_s; typedef struct elevator_s elevator_t; struct request_list { unsigned int count; struct list_head free; wait_queue_head_t wait; }; struct request { struct list_head queuelist; /* looking for ->queue? you must _not_ * access it directly, use * blkdev_dequeue_request! */ void *elevator_private; unsigned char cmd[16]; unsigned long flags; /* see REQ_ bits below */ int rq_status; /* should split this into a few status bits */ kdev_t rq_dev; int errors; sector_t sector; unsigned long nr_sectors; unsigned long hard_sector; /* the hard_* are block layer * internals, no driver should * touch them */ unsigned long hard_nr_sectors; /* Number of scatter-gather DMA addr+len pairs after * physical address coalescing is performed. */ unsigned short nr_phys_segments; /* Number of scatter-gather addr+len pairs after * physical and DMA remapping hardware coalescing is performed. * This is the number of scatter-gather entries the driver * will actually have to deal with after DMA mapping is done. */ unsigned short nr_hw_segments; unsigned int current_nr_sectors; unsigned int hard_cur_sectors; void *special; char *buffer; struct completion *waiting; struct bio *bio, *biotail; request_queue_t *q; struct request_list *rl; }; /* * first three bits match BIO_RW* bits, important */ enum rq_flag_bits { __REQ_RW, /* not set, read. set, write */ __REQ_RW_AHEAD, /* READA */ __REQ_BARRIER, /* may not be passed */ __REQ_CMD, /* is a regular fs rw request */ __REQ_NOMERGE, /* don't touch this for merging */ __REQ_STARTED, /* drive already may have started this one */ __REQ_DONTPREP, /* don't call prep for this one */ /* * for IDE */ __REQ_DRIVE_CMD, __REQ_DRIVE_TASK, __REQ_DRIVE_ACB, __REQ_PC, /* packet command (special) */ __REQ_BLOCK_PC, /* queued down pc from block layer */ __REQ_SENSE, /* sense retrival */ __REQ_SPECIAL, /* driver special command */ __REQ_NR_BITS, /* stops here */ }; #define REQ_RW (1 << __REQ_RW) #define REQ_RW_AHEAD (1 << __REQ_RW_AHEAD) #define REQ_BARRIER (1 << __REQ_BARRIER) #define REQ_CMD (1 << __REQ_CMD) #define REQ_NOMERGE (1 << __REQ_NOMERGE) #define REQ_STARTED (1 << __REQ_STARTED) #define REQ_DONTPREP (1 << __REQ_DONTPREP) #define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD) #define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK) #define REQ_DRIVE_ACB (1 << __REQ_DRIVE_ACB) #define REQ_PC (1 << __REQ_PC) #define REQ_SENSE (1 << __REQ_SENSE) #define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC) #define REQ_SPECIAL (1 << __REQ_SPECIAL) #define REQ_DRIVE_TASKFILE REQ_DRIVE_ACB #include <linux/elevator.h> typedef int (merge_request_fn) (request_queue_t *, struct request *, struct bio *); typedef int (merge_requests_fn) (request_queue_t *, struct request *, struct request *); typedef void (request_fn_proc) (request_queue_t *q); typedef request_queue_t * (queue_proc) (kdev_t dev); typedef int (make_request_fn) (request_queue_t *q, struct bio *bio); typedef int (prep_rq_fn) (request_queue_t *, struct request *); typedef void (unplug_device_fn) (void *q); enum blk_queue_state { Queue_down, Queue_up, }; /* * Default nr free requests per queue, ll_rw_blk will scale it down * according to available RAM at init time */ #define QUEUE_NR_REQUESTS 8192 struct request_queue { /* * Together with queue_head for cacheline sharing */ struct list_head queue_head; struct list_head *last_merge; elevator_t elevator; /* * the queue request freelist, one for reads and one for writes */ struct request_list rq[2]; request_fn_proc *request_fn; merge_request_fn *back_merge_fn; merge_request_fn *front_merge_fn; merge_requests_fn *merge_requests_fn; make_request_fn *make_request_fn; prep_rq_fn *prep_rq_fn; /* * The VM-level readahead tunable for this device. In * units of 512-byte sectors. */ unsigned ra_sectors; /* * The queue owner gets to use this for whatever they like. * ll_rw_blk doesn't touch it. */ void *queuedata; /* * queue needs bounce pages for pages above this limit */ unsigned long bounce_pfn; int bounce_gfp; /* * This is used to remove the plug when tq_disk runs. */ struct tq_struct plug_tq; /* * various queue flags, see QUEUE_* below */ unsigned long queue_flags; /* * protects queue structures from reentrancy */ spinlock_t *queue_lock; /* * queue settings */ unsigned short max_sectors; unsigned short max_phys_segments; unsigned short max_hw_segments; unsigned short hardsect_size; unsigned int max_segment_size; unsigned long seg_boundary_mask; wait_queue_head_t queue_wait; }; #define RQ_INACTIVE (-1) #define RQ_ACTIVE 1 #define RQ_SCSI_BUSY 0xffff #define RQ_SCSI_DONE 0xfffe #define RQ_SCSI_DISCONNECTING 0xffe0 #define QUEUE_FLAG_PLUGGED 0 /* queue is plugged */ #define QUEUE_FLAG_CLUSTER 1 /* cluster several segments into 1 */ #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) #define blk_mark_plugged(q) set_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) #define blk_queue_empty(q) elv_queue_empty(q) #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) #define rq_data_dir(rq) ((rq)->flags & 1) /* * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may * it already be started by driver. */ #define rq_mergeable(rq) \ (!((rq)->flags & (REQ_NOMERGE | REQ_STARTED | REQ_BARRIER)) \ && ((rq)->flags & REQ_CMD)) /* * noop, requests are automagically marked as active/inactive by I/O * scheduler -- see elv_next_request */ #define blk_queue_headactive(q, head_active) extern unsigned long blk_max_low_pfn, blk_max_pfn; /* * standard bounce addresses: * * BLK_BOUNCE_HIGH : bounce all highmem pages * BLK_BOUNCE_ANY : don't bounce anything * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary */ #define BLK_BOUNCE_HIGH (blk_max_low_pfn << PAGE_SHIFT) #define BLK_BOUNCE_ANY (blk_max_pfn << PAGE_SHIFT) #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) extern int init_emergency_isa_pool(void); extern void create_bounce(unsigned long pfn, int gfp, struct bio **bio_orig); extern inline void blk_queue_bounce(request_queue_t *q, struct bio **bio) { create_bounce(q->bounce_pfn, q->bounce_gfp, bio); } #define rq_for_each_bio(bio, rq) \ if ((rq->bio)) \ for (bio = (rq)->bio; bio; bio = bio->bi_next) struct blk_dev_struct { /* * queue_proc has to be atomic */ request_queue_t request_queue; queue_proc *queue; void *data; }; struct sec_size { unsigned block_size; unsigned block_size_bits; }; /* * Used to indicate the default queue for drivers that don't bother * to implement multiple queues. We have this access macro here * so as to eliminate the need for each and every block device * driver to know about the internal structure of blk_dev[]. */ #define BLK_DEFAULT_QUEUE(_MAJOR) &blk_dev[_MAJOR].request_queue extern struct sec_size * blk_sec[MAX_BLKDEV]; extern struct blk_dev_struct blk_dev[MAX_BLKDEV]; extern void grok_partitions(kdev_t dev, long size); extern int wipe_partitions(kdev_t dev); extern void register_disk(struct gendisk *dev, kdev_t first, unsigned minors, struct block_device_operations *ops, long size); extern void generic_make_request(struct bio *bio); extern inline request_queue_t *blk_get_queue(kdev_t dev); extern void blkdev_release_request(struct request *); extern void blk_attempt_remerge(request_queue_t *, struct request *); extern struct request *blk_get_request(request_queue_t *, int, int); extern void blk_put_request(struct request *); extern void blk_plug_device(request_queue_t *); extern void blk_recount_segments(request_queue_t *, struct bio *); extern inline int blk_phys_contig_segment(request_queue_t *q, struct bio *, struct bio *); extern inline int blk_hw_contig_segment(request_queue_t *q, struct bio *, struct bio *); extern int block_ioctl(kdev_t, unsigned int, unsigned long); extern int ll_10byte_cmd_build(request_queue_t *, struct request *); /* * get ready for proper ref counting */ #define blk_put_queue(q) do { } while (0) /* * Access functions for manipulating queue properties */ extern int blk_init_queue(request_queue_t *, request_fn_proc *, spinlock_t *); extern void blk_cleanup_queue(request_queue_t *); extern void blk_queue_make_request(request_queue_t *, make_request_fn *); extern void blk_queue_bounce_limit(request_queue_t *, u64); extern void blk_queue_max_sectors(request_queue_t *q, unsigned short); extern void blk_queue_max_phys_segments(request_queue_t *q, unsigned short); extern void blk_queue_max_hw_segments(request_queue_t *q, unsigned short); extern void blk_queue_max_segment_size(request_queue_t *q, unsigned int); extern void blk_queue_hardsect_size(request_queue_t *q, unsigned short); extern void blk_queue_segment_boundary(request_queue_t *q, unsigned long); extern void blk_queue_assign_lock(request_queue_t *q, spinlock_t *); extern void blk_queue_prep_rq(request_queue_t *q, prep_rq_fn *pfn); extern int blk_set_readahead(kdev_t dev, unsigned sectors); extern unsigned blk_get_readahead(kdev_t dev); extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); extern void blk_dump_rq_flags(struct request *, char *); extern void generic_unplug_device(void *); extern int * blk_size[MAX_BLKDEV]; /* in units of 1024 bytes */ extern int * blksize_size[MAX_BLKDEV]; #define MAX_PHYS_SEGMENTS 128 #define MAX_HW_SEGMENTS 128 #define MAX_SECTORS 255 #define MAX_SEGMENT_SIZE 65536 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) extern void drive_stat_acct(struct request *, int, int); extern inline void blk_clear(int major) { blk_size[major] = NULL; #if 0 blk_size_in_bytes[major] = NULL; #endif blksize_size[major] = NULL; } extern inline int get_hardsect_size(kdev_t dev) { request_queue_t *q = blk_get_queue(dev); int retval = 512; if (q && q->hardsect_size) retval = q->hardsect_size; return retval; } #define blk_finished_io(nsects) do { } while (0) #define blk_started_io(nsects) do { } while (0) /* assumes size > 256 */ extern inline unsigned int blksize_bits(unsigned int size) { unsigned int bits = 8; do { bits++; size >>= 1; } while (size > 256); return bits; } extern inline unsigned int block_size(kdev_t dev) { int retval = BLOCK_SIZE; int major = major(dev); if (blksize_size[major]) { int minor = minor(dev); if (blksize_size[major][minor]) retval = blksize_size[major][minor]; } return retval; } static inline loff_t blkdev_size_in_bytes(kdev_t dev) { #if 0 if (blk_size_in_bytes[major(dev)]) return blk_size_in_bytes[major(dev)][minor(dev)]; else #endif if (blk_size[major(dev)]) return (loff_t) blk_size[major(dev)][minor(dev)] << BLOCK_SIZE_BITS; else return 0; } typedef struct {struct page *v;} Sector; unsigned char *read_dev_sector(struct block_device *, unsigned long, Sector *); static inline void put_dev_sector(Sector p) { page_cache_release(p.v); } #endif |